Self-centering chuck for rock-drills.



G. H. GILWIAN.

SELF CENTERING CHUCK FR ROCK DRILLS.

APPLlcAnoN FILED JAN. 6. 1913.

Patented D66. 5, 19116.

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GEORGE H. GILMAN, 0F CLAREMONT, NEW HAMPSHIRE, ASSIGNOR, BY MESNE ASSIGN MENTS, T0 THE SULLIVAN MACHINERY COMPANY, OF BOSTON, MASSACHUSETTS, A

CORPORATION 0F MASSACHUSETTS.

Specification of Letters Patent.

Patented Dec. 5, 1916.

Application led January 6, 1913. Serial No. 740,270.

clusively, to rock drill chucks, and will bebest understood by reference to the follow ing specification, whentaken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings z-Figure 1 is an elevation of a drill-holding chuck embodying my invention; Fig. 2-is an end elevation of the chuck, as viewed from the left-hand side of Fig. 1; the drill steel being shown in section; Fig. 3 is a cross-sectional view on line 3-3 of Fig. 1; Fig. 4 is a longitudinal sectional view on line 4-4 of Fig. 1, the drill steel and drill-clamping blocks being shown in elevation; and Fig. 5 is a similar section, showing the blocks and wedge retracted, the blocks being shown in their non-clamping position. Fig. 6 is a perspective view of one of the holding blocks or drillengaging members.

Referring to the drawings, and tothe embodiment of my invention which I have there disclosed for illustrative purposes, I have there shown a piston rod 6, having an enlarged end portion 7, which constitutes the holder of the chuck. This holder is provided with a longitudinally tapered recess 8, opening out of the forward end thereof, and is provided with a plurality of lateral apertures, herein two, designated b-y the numerals 9 and 10, leading outward from said recess, preferably at the rear end of the latter.

rIhe recess 8` receives a plurality of chuck blocks, or drill-engaging members, herein two designated by the numerals 11 and 12. The exterior surface of the block 12 has a taper corresponding to the taper of the recess 8, while the exterior surface of the block 11 converges forwardly, with relation to the adjacent surface of the recess, and between the latter surfaces there is placed a tapered key or wedge 13, for a purpose which will presently appear. The opposed converging bearing surfaces 14 and 15 of the recess 8 are preferably so shaped as to insure a full bearing for the wedge 13 and block 12 at all positions. To this end, the surfaces 14 and 15 are preferably of substantially uniform crosssectional shape throughout theii` respective lengths, and

herein, the surface 14 is `flat, while the surface 15 is substantially semi-cylindrical, and the wedge 13 and block 12 are correspondingly shaped. It should also be noted that the recess 8 is provided opposite the semicylindrical surface 15 with a corresponding semi-cylindrical surface 15', and that the block 11 (see Figs. 2 and 4) has a corresponding semi-cylindrical shape, except that it is flattened at 14, as already described, for engagement with the wedge 13. It should also be noted -that the block 11 is grooved for approximately one-half its length from the rear end toward the front end thereof to receive the wedge 18, whereby on both sides of the latter, there is provided a ridge which is indicated at 26 by dotted lines in Figs. 2, 4 and 5. It will now be evident that the block 11 has a tapered formation from front to rear, and that its obliquely disposed cylindrical surface corresponds exactly with the obliquely disposed cylindrical surface 15 of the block 12, whereby they may be caused automatically to center the drill by simply providing suitable interengaging means to cause them to move simultaneously in an axial direction. It will be understood, however, that the cross-sectional shape of these surfaces may be appropriately varied to suit the requirements.

The inner surfaces of the blocks 11 and 12 are suitably shaped to receive a drill steel 16, -wh-ich maybe of any suitable cross-sectional Ishape, the blocks for this purpose being provided with longitudinal grooves 17 and 18, respectively. The blocks are provided with suitable interengaging means to eEect their mutual longitudinal movement, and prevent them from coming out of place except when properly manipulated by the operator, such vmeans herein comprising a pair of lugs 19--19onthe block 10, projecting into the corresponding recesses 20--20 in the block 11, the depth of Ythese recesses being such as to permit the blocks to approach each other to a sufiicient'extent to grip the smallest drill steel within thecapacity of the chuck. The shape of the blocks is such that, when the drill steel is removed, they may be withdrawn rearwardly and then outwardly through the apertures 9 and 10.

Preferably, the block 12 is provided at its rear end with a lug 21, enabling the block .to be conveniently manipulated and driven Yin either direction by striking on the lug Yso The drill steel is first placed between the chuck blocks with the latter retracted, as

shown in Fig. 5, and the rear end of the drill steel abutting against a suitable abutment, herein in the form of a. hardened block of steel 25, inserted in a holder at the rear end of the recess 8. The wedge 13 is placed.

in rits retracted position shown in Fig. 5, after whichthe blocks 11 and 12 are pushed forward and driven lightly into place, so as to grip the drill steel therebetween.

. Finally, the tapered wedge or key 13 is driven forward, and its taper is such as to cause the blocks to grip the drill steel with a very firm clamping action, and yet permit them to be released very readily by driving the' wedge in arrearward direction. When in operation,the chuck is automatically selftightening, dueto thevfact that with each blow of the drill steel on the work, the'inertia of the blocks automatically tends to driveV them forwardV in their holder. The interlockin y ,nat-ure of the blocks accomplifshes the desired self-centering of the drill withrelationto theV piston and piston'rod, since the' -blocks' 'must always move 1n unison. flt willV be understood, of course,

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thatf the blocks werenot interlockingfone VVmio'fhtbe .forced 'ahead ofthe other, in which vk"case', .the drill wouldbe thrown out of line with the.' piston rod. To .remove the drill,

Vitis only. necessary to,V first drive the wedge l in a rearwarddirection, until the .lug 23 bringsnp against theY frontV face of the vholder 7, afterwhich alight tap onthe lug Q21 willfse'rve tojfully retract theblocks 11A l kandrll'thus freeing the Vdrill, steel, Vand al-V Y Y f lovvingithe latter to Ybewithdrawn.V

l,While l,havezhereinV shown and described one ,embodiment of my Vinvention for illus- 'Y trative purposes, `and have disclosed' andV discussed in detail the construction and ar- Y,that extensive deviations from the illustrated form or embodiment of the invention may be made without departing from the principles thereof.

Having thus described my invention, what l claim and desire by Letters Patent to procure is 1. A chuck having, in combination, means for utilizing the blow of the drill upon the work for centering and maintaining the drill in centered position, and means for clamping said first mentioned means.

2. The combination, with a drill, of a chuck havingy means for utilizing the blow of the drill upon the work to maintain the drill in centered position, and means for producing a drill clamping action of said rst mentioned means.

3. A chuck having, in combination, a holder, means coperating therewith'including a plurality of blocks having forwardly converging surfaces for utilizing the blow of the drill upon the work for maintaining the drill in centered position, and means for producing a drill clamping action of said blocks.

4. A self-centering chuck having, in combination, avholder inertia-controlled means cooperating therewith including a plurality of longitudinally slidable clamping members for utilizing .the blow of the drill upon the work for maintaining the drill in ccntei-ed and clamped position by their longitudinal sliding action, and a wedge interposed between one of .said clamping members and a relatively fixed surface of said holder.. I

5. A chuck having, in combination, a holder provided with a recess opening out of its forward end, a ,plurality of members located in said recess and having their outer surfaces converging toward the forward end, one vof said members being engageable with a drill and another drill engaging member interposed between the irstlmentione'd members.

. 6. A drill chuck having, in combination, a` holder provided with a recess having opposit@J sides converging toward the forward end' of the holder, a plurality of chuck blocks located in said recess, and a tapered key interposedbetween one of said blocks and the adjacent surface of said recess.

7.'A drill chuck having,vin combination,

a holder provided with a recess opening out of its forward end and having opposed surfaces converging toward the forward end, a plurality of drill-engaging members located in said recess and between said con- 1,207,549 l1 lr verging surfaces, one of said members being tapered and a tapered member interposed between and having converging surfaces engaging the other o-f said drill-engaging members and the adjacent internal surface of said recess.

8. A drill chuck having, in combination, a holder provided with a longitudinally tapered recess opening out of one end thereof and having opposite sides converging toward said open end, a plurality of chuck blocks located in said recess, one of said blocks being tapered and a wedge interposed between the other of said blocks and the adjacent side of said recess, said wedge having its wedging surfaces converging toward the forward end of said chuck.

9. A drill chuck having, in combination, a holder provided with a longitudinally tapered recess having opposite sides converging toward the longitudinal median line of the chuck, a plurality of inter-engaging chuck-blocks located in said recess, one of said blocks engaging one of said sides, and a wedge interposed between and having its wedging surfaces engaging the other side of said recess and the external surface of the adjacent chuck-block.

10. A drill chuck having, in combination, a holder provided with a longitudinally tapered recess opening out of one end thereof, and lateral apertures leading out of said recess, a plurality of clamping blocks located in said recess, one of said blocks engaging the adjacent surface of said recess, and a wedge interposed between the other of said blocks and the adjacent surface of said recess.

11. A drill chuck having, in combination, a holder provided with a longitudinally tapered recess opening out of one end thereof, and lateral apertures leading out of said recess, a plurality of clamping blocks located in said recess, one of said blocks engaging the adjacent surface of said recess, and a wedge interposed between the other of said blocks and the adjacent surface of said recess, said wedge being provided with a lug projecting out of one of said apertures.

12. A drill chuck having, in combination, a holder' provided with a longitudinally ta pered recess opening out of one end thereof, and lateral apertures leading out of said recess, a plurality of clamping blocks located in said recess, one of said blocks being provided with a lug projecting out of blocks and the adjacent surface of said reces-s, said wedge having a lug projecting from the other of said apertures.

13. A self-centering chuck having, in combination, a holder inertia-controlled means coperating therewith including a plurality of clamping members for utilizing the blow of the drill upon the work for maintaining the drill in centered and clamped position, and a wedge interposed between one of said clamping members and a relatively flXed surface of said holder, said wedge being provided with a lug adjacent one end thereof.

14. A self-centering chuck having, in combination, a holder inertia-controlled means coperating therewith includingl a plurality of clamping members for utilizing the blow of the drill upon the work for maintaining the drill in centered and clamped position, and a wedge interposed between one of said clamping members and a relatively fixed surface of said holder, said wedge being provided with lugs adjacent opposite ends thereof.'

15. A chuck having, in combination, a holder, means coperating therewith for utilizing the blow of the drill upon the work for maintaining the drill in centered position, means for clamping said first mentioned means, and means for limiting the movement of said last mentioned means.

16. In a drill chuck, a holder having a tapered longitudinally disposed recess therein, coperating drill engaging members disposable on opposite sides of the drill and having coperating tapered surfaces engaging the wall of the recess in said holder, one of said members also having a flat face, and a wedge interposed between said face and said holder.

17. In a drill chuck, a holder having a tapered longitudinally disposed recess therein provided with a communicating recess, coperating drill engaging members disposable on opposite sides of the drill and having cooperating tapered surfaces engageable with the wall of the tapered recess in said holder, one of said members also having a flat face, and a wedge member engageable with said flat face and receivable in the communicating recess in said holder.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GEORGE H. GILMAN.

Vtitnesses:

E. J. BURGHARD, IRENE KELLEY.

Uopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

